Cytomorphological alterations of thyroid gland consequent upon fluorosis

Background: Study aimed at assessing the impact of elevated fluoride from drinking water on thyroid gland structure and function in fluorosis prone areas. Iodine is incorporated in the thyroid synthesis by thyroid gland but in the presence of low Iodine levels fluoride is likely to interfere with the concentrating capacity of thyroid of iodine in thyroid production, consequently reflecting changes in thyroid parameters and also cytomorphological features manifesting hypothyroidism in association with different pathological entities.Methods: Prakasam district in Andhra Pradesh is fluorosis prone zone and subjects are picked up from highly vulnerable zone in this district and their specimens are collected to study cytomorphological changes of the thyroid gland and biochemical parameters of blood samples for thyroid function test were considered. Cytological study by way of Fine Needle Aspiration Cytology (FNAC) of thyroid gland, biochemical parameters pertaining to function of thyroid gland namely Free triiodothyronine (FT3), Free Thyroxine (FT4) and Thyroid stimulating hormone (TSH) were assessed in the subjects from fluorosis prone zone.Results: The results were statistically significant with concurrent association of different cytological alterations of thyroid gland in these subjects like Hashimoto’s thyroiditis of hypothyroidism, adenomatous goitre, colloid goitre and few of follicular adenoma/neoplasm. FNAC makes cytological changes evident showing different morphological features that comprise different pathological entities largely with an evidence of hypothyroidism in most of the cases in the given study.Conclusions: The results of the study strongly suggest assessing the magnitude of the problem of fluorosis and also magnitude of its influence on thyroid structure and function that warrants assessment of the thyroid function by biochemical and cytological studies

Sub-Optimal Algorithms for Force Distribution in Multifingered Grippers

The work described in this paper addresses the problem of determination of the appropriate distribution of forces between the fingers of a multifingered gripper grasping an object. The system is statically indeterminate and an optimal solution for this problem is desired for force control. A fast and efficient sub-optimal method for computing the grasping forces is presented. This method is based on the superposition of finger-interaction forces on equilibrating forces. An interaction force is defined as the component of the vector difference of the finger contact forces at any two fingers along the line joining the two contact points. They are computed based on the assumption that the normals at the point of contact pass through the centroid of the contact points and are therefore independent of the actual geometry of the object. The contact interaction is modelled as a point contact. The problems associated with making the algorithm independent of the object geometry are explored

Real Time Dense Depth Estimation by Fusing Stereo with Sparse Depth Measurements

We present an approach to depth estimation that fuses information from a stereo pair with sparse range measurements derived from a LIDAR sensor or a range camera. The goal of this work is to exploit the complementary strengths of the two sensor modalities, the accurate but sparse range measurements and the ambiguous but dense stereo information. These two sources are effectively and efficiently fused by combining ideas from anisotropic diffusion and semi-global matching. We evaluate our approach on the KITTI 2015 and Middlebury 2014 datasets, using randomly sampled ground truth range measurements as our sparse depth input. We achieve significant performance improvements with a small fraction of range measurements on both datasets. We also provide qualitative results from our platform using the PMDTec Monstar sensor. Our entire pipeline runs on an NVIDIA TX-2 platform at 5Hz on 1280x1024 stereo images with 128 disparity levels.Comment: 7 pages, 5 figures, 2 table

Force Distribution in Closed Kinematic Chains

The problem of force distribution in systems involving multiple frictional contacts between actively coordinated mechanisms and passive objects is examined. The special case in which the contact interaction can he modeled by three components of forces (zero moments) is particularly interesting. The Moore-Penrose Generalized Inverse solution for such a model (point contact) is shown to yield a solution vector such that the difference between the forces at any two contact points projected along the line joining the two points vanishes. Such a system of contact forces is described by a helicoidal vector field which is geometrically similar to the velocity field in a rigid body twisting about an instantaneous screw axis. A method to determine this force system is presented. The possibility of superposing another force field which constitutes the null system is also investigated

Visual Servoing of a UGV from a UAV using Differential Flatness

In this paper the problem of controlling the motion of a nonholonomic vehicle along a desired trajectory using observations from an overhead camera is considered. The control problem is formulated in the image plane. We show that the system in the image plane is differentially flat and use this property to generate effective control strategies using only visual feedback. Simulation results illustrate the methodology and show robustness to errors in the camera calibration parameters

Calibrating an Air-Ground Control System from Motion Correspondences

In this paper we consider the problem of controlling the motion of a vehicle moving on a ground plane based on aerial imagery. In the course of this work we propose a novel analysis of the relationship between the velocity of the vehicle on the ground plane and the velocity of its projection in the image. We show that this relationship provides information about a subset of the parameters of the homography relating the ground plane to the aerial image plane and describe how we can recover this relationship from available measurements